Apparatus to inject treatment substances, which may be liquids or gases, is well-developed. One well-known device is an aspirating injector of the type shown in Mazzei patent No. 4,123,800, issued Oct. 31, 1978, which is incorporated herein by reference for its showing of injection of treatment substances into water, and an injector for doing so.
The purpose of such an injector is to bring a proportioned amount of the substance into a stream flowing through a pipe in which it is plumbed. In addition to this metering objective, it is desired to have the treatment substance well-dissolved, and distributed throughout the flowing stream of water. This is especially important when gases are introduced. The efficiency of dissolving a gas into a stream is heavily dependent on the surface area of the bubbles after the gas is injected, and of the movement of the bubbles in the stream. A vigorous movement of bubbles, and reduction in their size, will accelerate the solution of the gas. Vigorous movement also assists the distribution and solution of liquids.
This accelerated distribution of gas, and breaking its bubbles into smaller bubbles to increase the total gas liquid interface can also improve a stripping action in which one gas is entrained in the water stream for the purpose of removing a different gas from the stream. An example of this action will be found in Mazzei patent No. 5,674,312 issued Oct. 7, 1997.
Nozzles made according to the said Mazzei patent continue to perform to high standards of accuracy in metering and mixing of treatment substances into a water stream. However, it has been found that the Mazzei device can be improved so as to accelerate the solution and mixing of the treatment substances into the water stream without an appreciable sacrifice of energy. This can provide important advantages, among them a reduction in capital cost and size of the installation. Because the treatment substance--especially for gases but also for liquids--can be dissolved (gases) and mixed (both gases and liquids) more quickly, the size of the installation and its components can be reduced because there is less need for system volume downstream from the injector for completion of the solution and mixing.
It is an object of this invention to provide a more efficient mixer-injector of the general type shown in the said Mazzei patents.